Philae awakes: What next for probe after 7 month nap on comet?

What a wake-up call. On Saturday night, the German Aerospace Center (DLR) in Cologne received 85 seconds of incredibly good news: a data chirp from the missing European Space Agency lander Philae. Despite seven months adrift and alone on comet 67P/Churyumov-Gerasimenko since its bumpy landing last year, Philae is back and ready for science.

“Philae is doing very well – it has an operating temperature of -35 °C and has 24 watts of power available,” said lander manager Stephan Ulamec. “The lander is ready for operations.” Here is what’s next:

Philae has finally made contact, but only intermittently, so the first order of business is establishing a better link. The lander speaks to Earth via the orbiting Rosetta satellite, meaning communication is only possible during certain windows when the spacecraft is overheard.

Philae only transmitted for a minute and a half out of a possible 2-hour window, meaning the link isn’t ideal, and the lander team heard nothing during a broadcast window on Sunday. Reorienting Rosetta should help, said ESA project scientist Matt Taylor.

The mission team was able to download and analyse 300 data packets from Philae during its brief communication on Saturday, but they revealed that over 8000 more are sitting in the lander’s memory awaiting transmission. That suggests Philae has been operational recently but unable to transmit, so downloading this data will give the team clues about what the lander has experienced in the past few days.

The researchers and engineers behind Philae have had months to prepare for the lander’s reawakening, and have been planning sequences of short commands that can be performed quickly without stressing its battery.

Once communications are properly established, the team will upload the commands in the hope of gathering more scientific data about comet 67P. First on the list are the temperature and magnetic field readings, with the possibility of more images from the surface to come later.